ElementWrapper`1.cs

namespace Legerity;

using System;

using Legerity.Exceptions;

using OpenQA.Selenium;
using OpenQA.Selenium.Appium;
using OpenQA.Selenium.Support.UI;

/// <summary>
/// Defines a base wrapper for elements to expose platform element logic.
/// </summary>
/// <typeparam name="TElement">
/// The type of <see cref="AppiumWebElement"/>.
/// </typeparam>
public abstract class ElementWrapper<TElement> : IElementWrapper<TElement>
    where TElement : AppiumWebElement
{
    private readonly WeakReference elementReference;

    /// <summary>
    /// Initializes a new instance of the <see cref="ElementWrapper{TElement}"/> class.
    /// </summary>
    /// <param name="element">
    /// The <typeparamref name="TElement"/> reference.
    /// </param>
    protected ElementWrapper(TElement element)
    {
        this.elementReference = new WeakReference(element);
    }

    /// <summary>Gets the original <typeparamref name="TElement"/> reference object.</summary>
    public TElement Element =>
        this.elementReference is { IsAlive: true }
            ? this.elementReference.Target as TElement
            : null;

    /// <summary>
    /// Gets the driver used to find this element.
    /// </summary>
    public IWebDriver ElementDriver => this.Element.WrappedDriver;

    /// <summary>
    /// Gets a value indicating whether the element is visible.
    /// </summary>
    /// <exception cref="StaleElementReferenceException">Thrown when an element is no longer valid in the document DOM.</exception>
    public virtual bool IsVisible => this.Element.Displayed;

    /// <summary>
    /// Gets a value indicating whether the element is enabled.
    /// </summary>
    /// <exception cref="StaleElementReferenceException">Thrown when an element is no longer valid in the document DOM.</exception>
    public virtual bool IsEnabled => this.Element.Enabled;

    /// <summary>
    /// Clicks the element.
    /// </summary>
    /// <exception cref="InvalidElementStateException">Thrown when an element is not enabled.</exception>
    /// <exception cref="ElementNotVisibleException">Thrown when an element is not visible.</exception>
    /// <exception cref="StaleElementReferenceException">Thrown when an element is no longer valid in the document DOM.</exception>
    public virtual void Click()
    {
        this.Element.Click();
    }

    /// <summary>
    /// Gets the value of the specified attribute for this element.
    /// </summary>
    /// <param name="attributeName">The name of the attribute.</param>
    /// <returns>The attribute's current value if it exists; otherwise, null.</returns>
    /// <exception cref="StaleElementReferenceException">Thrown when an element is no longer valid in the document DOM.</exception>
    public string GetAttribute(string attributeName)
    {
        return this.Element.GetAttribute(attributeName);
    }

    /// <summary>
    /// Finds a child element by the specified locator.
    /// </summary>
    /// <param name="locator">The locator to find a child element by.</param>
    /// <returns>The <typeparamref name="TElement"/>.</returns>
    /// <exception cref="NoSuchElementException">Thrown when no element matches the expected locator.</exception>
    public AppiumWebElement FindElement(By locator)
    {
        return this.Element.FindElement(locator);
    }

    /// <summary>
    /// Determines whether the given element is not shown.
    /// </summary>
    /// <param name="locator">
    /// The locator for the element to locate.
    /// </param>
    /// <exception cref="ElementShownException">Thrown when the element is shown for the expected locator.</exception>
    /// <exception cref="NoSuchElementException">Thrown when no element matches the expected locator.</exception>
    public void VerifyElementNotShown(By locator)
    {
        try
        {
            this.VerifyElementShown(locator);
            throw new ElementShownException(locator.ToString());
        }
        catch (ElementNotShownException)
        {
        }
    }

    /// <summary>
    /// Determines whether the given element is shown.
    /// </summary>
    /// <param name="locator">
    /// The locator for the element to find.
    /// </param>
    /// <exception cref="ElementNotShownException">Thrown when an element is not shown for the expected locator.</exception>
    /// <exception cref="NoSuchElementException">Thrown when no element matches the expected locator.</exception>
    public void VerifyElementShown(By locator)
    {
        this.VerifyElementShown(locator, null);
    }

    /// <summary>
    /// Determines whether the specified element is shown with the specified timeout.
    /// </summary>
    /// <param name="locator">The locator to find a specific element.</param>
    /// <param name="timeout">
    /// The amount of time the driver should wait when searching for the <paramref name="locator"/> if it is not immediately present.
    /// </param>
    /// <exception cref="ElementNotShownException">Thrown when an element is not shown for the expected locator.</exception>
    /// <exception cref="NoSuchElementException">Thrown when no element matches the expected locator.</exception>
    public void VerifyElementShown(By locator, TimeSpan? timeout)
    {
        if (timeout == null)
        {
            try
            {
                if (this.Element.FindElement(locator) == null)
                {
                    throw new ElementNotShownException(locator.ToString());
                }
            }
            catch (NoSuchElementException ex)
            {
                throw new ElementNotShownException(locator.ToString(), ex);
            }
        }
        else
        {
            var wait = new WebDriverWait(this.Element.WrappedDriver, timeout.Value);
            wait.Until(driver => driver.FindElement(locator) != null);
        }
    }

    /// <summary>
    /// Determines whether the specified elements are shown.
    /// </summary>
    /// <param name="locator">
    /// The locator for the element to find.
    /// </param>
    /// <exception cref="ElementsNotShownException">Thrown when no elements are shown for the expected locator.</exception>
    public void VerifyElementsShown(By locator)
    {
        this.VerifyElementsShown(locator, null);
    }

    /// <summary>
    /// Determines whether the specified elements are shown with the specified timeout.
    /// </summary>
    /// <param name="locator">
    /// The locator to find a collection of elements.
    /// </param>
    /// <param name="timeout">
    /// The amount of time the driver should wait when searching for the <paramref name="locator"/> if it is not immediately present.
    /// </param>
    /// <exception cref="ElementsNotShownException">Thrown when no elements are shown for the expected locator.</exception>
    public void VerifyElementsShown(By locator, TimeSpan? timeout)
    {
        if (timeout == null)
        {
            if (this.Element.FindElements(locator).Count == 0)
            {
                throw new ElementsNotShownException(locator.ToString());
            }
        }
        else
        {
            var wait = new WebDriverWait(this.Element.WrappedDriver, timeout.Value);
            wait.Until(driver => driver.FindElements(locator).Count != 0);
        }
    }
}